Genome variation induced by change of the ploidy level in Paspalum notatum

MARTELOTTO L; STEIN J; ORTIZ JPA; ESPINOZA F; QUARIN CL; PESSINO SC

Pinamar (Buenos Aires)

Congreso; XLI Reunión Anual Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2005

GENOME VARIATION INDUCED BY A CHANGE OF THE PLOIDY LEVEL IN PASPALUM NOTATUM Martelotto L1, Stein J1, Ortiz JP1, Espinoza F2, Quarin C2, Pessino S1.1Plant Research Central Laboratory, Department of Agronomy, National University of Rosario, Parque Villarino, 2125 Zavalla, Argentina. 2Institute of Botany of the North-East (IBONE), Sargento Cabral 2131, 3400 Corrientes, Argentina. E-mail: lucianomartelotto@yahoo.comMartelotto L1, Stein J1, Ortiz JP1, Espinoza F2, Quarin C2, Pessino S1.1Plant Research Central Laboratory, Department of Agronomy, National University of Rosario, Parque Villarino, 2125 Zavalla, Argentina. 2Institute of Botany of the North-East (IBONE), Sargento Cabral 2131, 3400 Corrientes, Argentina. E-mail: lucianomartelotto@yahoo.com Genetic and epigenetic changes accompany allopolyploid formation in several plant species. Similar changes have not yet been examined in autopolyploids. The aim of this work was to investigate the existence of early variation in genome sequence and methylation status taking place after autopolyploidization in P. notatum. The genetic structures of a diploid genotype and its autotetralploid derivative were compared by RAPD and AFLP markers, revealing ~9.5% of polymorphisms. The frequency of lost and gained bands suggest that sequence loss and/or insertion of repetitive sequences might be major forces of genome variation. Genomic Southern blots with/without methylation-sensitive restriction enzymes confirmed that at least some of the polymorphic loci were repetitive. Neither epigenetic modifications nor sequence elimination were observed between lines. P. notatum. The genetic structures of a diploid genotype and its autotetralploid derivative were compared by RAPD and AFLP markers, revealing ~9.5% of polymorphisms. The frequency of lost and gained bands suggest that sequence loss and/or insertion of repetitive sequences might be major forces of genome variation. Genomic Southern blots with/without methylation-sensitive restriction enzymes confirmed that at least some of the polymorphic loci were repetitive. Neither epigenetic modifications nor sequence elimination were observed between lines.